Brown-violet sulfur dye and process of making same.



UNITED STATES PATENT FFICE.

ARTHUR W'EINBERG, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO LEOPOLDCASSELLA 85 00., OF FRANKFORT-ON-THE-MAIN, GERMANY.

BROWN-VIOLET SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION formingpart of Letters Patent No. 701,435, dated June 3,1902.

Application filed January 5, 1901. Renewed January 13, 1902. Serial No.89,592. (No specimens.)

To all w/tont it may concern:

Be it known that I, ARTHUR WEINBERG, a citizen of Prussia, and aresident of Frankforton-the-Main, in the Province of Hesse-Nassau andKingdom of Prussia, Germany, have invented certain new and usefulImprovements in Brownish-Violet Coloring-Matter and Processes of MakingSame, of which the following is a specification.

I have found that by heating oxyderivatives of bodies which contain anazin group with alkaline sulfids and sulfur valuable dyestuffs areobtained which from a bath containing sodium sulfid produce on cottonshades varying from violet to brown. It is advantageous, though notabsolutely necessary, it also amido groups are present besides one ormore hydroxyl groups. The amid'ooxyphenazin (Nietzki, Berichte (Z. (Z.Chem. Goa, XXVIII, 2975) of the formula may be considered atypicalstarting material. It yields a brownish-violet dyestuif. The samedyestuff is obtained if a sulfo group, a carboxyl group, or a halogenatom is substituted in this compound. For instance, theamidooxyphenazincarbonic acid temperature is then slowly raised to 140to 150 centigrade and heating continued until the melt dissolvescompletely in water with a black-violet shade and until a test of thesolution does not show a yellow border on filtering-paper. The melt isthen dried completely, and the thus-obtained crude dyestuif may servedirectly for dyeing purposes, or it is precipitated from the solution byneutralizing with an acid, filtered off, and dried. For dyeing purposesit must then be dissolved by means of sulfid of sodium. Thethus-produced dyestuff shows the following reactions: It dissolves inconcentrated sulfuric acid with a violet-black color and separates fromthis solution in the form of a violet precipitate by addition of water.It is soluble in caustic alkalies with a brown color, very easilysoluble in water in the presence of alkaline sulfids with. aviolet-black color. It dyes unmordanted cotton brownish violet shadeswhich are fast to washing, alkalies, acids, and

light.

Having thus described my invention and how it may be carried out, what Iclaim is- 1. The process of producing a brownishviolet dyestuff byheating oxyamidophenazin of the formula (in which a: stands forhydrogen, chlorin, a sulfo group or a carboxyl group) with alkalinesulfids and sulfur substantially as described.

2. The coloring-matter produced as hereinbefore described which is adark-violet or black powder, dissolving in concentrated sulfuric acidwith aviolet-black color being precipitated from this solution byaddition of water, easily soluble in water in presence of alkalinesulfids, dyeing unmordanted cotton brownish-violet shades fast towashing, alkalies, acids and light substantially as described.

Signed at Frankfort-on-the-Main, in the Province of Hesse-Nassau andKingdom of Prussia, this 18th day of December, A. D.

ARTHUR WEINBERG. Witnesses:

JEAN GEUND, CARL GRUND.

